#!/bin/bash
echo hello world
#printf "hello world"

#改变打印的颜色
#echo -e "\e[1;31m this is a test \e[0m"

#number=5
#name=apple

#为变量赋值
#echo "we have $number ${name}s"

#可以得出字符串长度
#echo ${#name}

#可知道当前使用到是哪一类shell
#echo $0
#echo $SHELL 

#判断是不是超级用户
If [ $UID -ne 0 ] ; then
    echo Non root user. Please run as root .
else
    echo Root user. 
fi

